Speed change pulley for drill presses



Jan. 19, 1954 P s 2,666,332

SPEED CHANGE PULLEY FOR DRILL PRESSES Filed May 8, 1952 M 2 Sheets-Sheet l INVENTOR. ROBERT D. PHA RES Jan. 19, 1954 R. D. PHARES SPEED CHANGE PULLEY FOR DRILL PRESSES 2 Sheets-Sheet 2 Filed May 8, 1952 R. S m E N m m H K m D T m 3 B W a 1 7 I A O a wvvvvw wz R W B {ior drill presses and the like.

v speedcliarig mechanism. as-it" 'Wbiild inbunted' on anrin' press Patented Jan. 1 9, 1954v CHANGE PULLEYFORDRILL a .UPRESSES l "was1m w s. a- I ll' lilication llllfayfi, 1952, Serial Nbs286i689 1 1 I 'Ijhis invention pertains to' speed change: pulleys ilvlore particularly the'stype' of'rpulleyaspeed changers here shown made-outi ofztwo speed change V belt pulleys having "axially sliding cen- Aral portions arrangedrto pay-'otitone---be1t while the second-"belt is .dr'a-wn; in in orderto-s'ecure a diiiferent, effective'idiameter --for'-each of the two h -t 7 1 Qne'of the objects of-theinvention is to'provide a speed change puiley'syst'em fondrill'presses "orotherli'ght power-driventools wherein two automatically woi-king'speed change pulleys are ;mo unted betweel r'a driving liulley on 'a motor shaft and driven pulley on iithe=zdril-l spindle -,shaft so that theymove in uni'son in awert'ical plane between the drivirig and driven pulleys'and :are' arranged so thatthey' miitually"compensate lfor axial displacement of iliherbltsi that takes place when e peed ratios are changed;

Another-5object is.-to 'provide a pulley bracket and system of pulleys mounted thereon; which are of the speed cha'inge 'type havin' a slidingfiny termediate pulley partarranged'for mounting on a drill press so :thatithe TatiOsobtainaUI'e are of theorder of one to twelveori'inore and' are much greater than any ratios which may'be'obtained by the use of a single speed change pulley of the type mentioned.

Another "object? is*'t0 provide a bracket and speed change pulley system',fas"above'stated-with 131* attain th'e' foregoing-objects by means of the devices; mechanism'and' structure illustrat'ed in tneaccompaiiying drawings 1 my imprc ed "JEF- ii're z'isapIam/iew-the of;-

?.Fi'gure 3 1s ai' ertieaEsIde-s "t'ionail doubIe "idiiali 'sfieedTc'hafige fiwlIeys; and the mounting mechanism and-mack et therfeforl drawn ona somewha't enlarged scale iiavmg a 'it ertieal 'colv attendant mechanism for varying the speed-ra- ;tio aiforded 'by this device;

Figure-Bis a--front "elevation thereof; and *:'-Figure 6 is a fragmentary side-elevation ofsaid speedfvarying mechanism taken substantially on ;1inej6 ;6 ofFigure4;

' Similar numerals refer 'to" similar parts the 'severalviews; -.4

' In'fFigure l'of the drawings the'mechanism'is shown'as'it'would appear mounted on adrill press column with the drill pr'ess "column '2" and *head oasting-3" and drill quill' l shown in dotted lines'to T'indi-cate their rel'ative positions. Nuine'ra-l =5 indicates 1 a driving pulley? mounted on motor-shaft '1, i and-numeral 8-' indicates a driveniiulley mounted 'ondrill'spindle shaft'9. r?

The speed change mechanism here concerned is generally indicated by'numeral 1 0; This includes (two speed 'chang'e pulleys l l and i2 mounted on shafts i 4 and: 'i 5; respectively? These shafts are mounted on abase bracket'l5-'-whieh is 'pivotally supported on the upper-en'ds-of parallel spaced links H? which'are, initurn,=pivbta11ysupported 'tween'the =two'bracketsare attached at" their ends "to-said brackets by'p'in's 28" which extend trans- 'verselytothe longitudinal extent ofsaid lorac'k ets and-"are proportioned and arranged to "maintain parallel alignment betweenbase bracket 'l 6 and column bracket 201 The column bracket haga 'm'ountiiig' ring "2 2 which fits over drill column 2 and may be hel'd'in place: by" as'et srewnw The forward; portion fll ofthis'bracket" extends longitudinallyf'orward fromtl'ie drill presscolomn and "ha-sits longitudinal'centeiin anaxiaiplane which -iiiay be rojec "dj"to"i'ne'l1ide the axis or motor (shaft Tandof die shaft affrheiongiwdmal cnter of base ac et leis'parallelto the center of column bracket a 24.j'1h motionfattaim atieby Bracket 16 an designated herein a'sffthe fspeed 'tiaryin'g motion l'i'es in this same plane; Bracket i6 is} shaped so that rear speed change p'un'ey i 2' onjs aft I5 is 'heldslightly-higherthan forward speed changepulley l l'. ;Pu1ley-l 2 isad- 'jacent' driving V-pulley -6, and pulley H is adjacent drivenpulley 13.-

Pulleysxi l -and-- I 2' are composite, and include the usualstructure attendant =toa' thi's type -bf speed-change" pull'eyahdhoth operate on Ger-tidal parallel tshatts whe'axesof sthese eshaft's also lie within th e' plan's-above nientionedr" In Order'- to steady tliese' shafts and' mai'rltain their relative position and parallelism a steadying link 26, having eyes 21 at each end, is attached to their upper ends.

The detailed structure of each of the pulleys II and I2 is conventional. However, in order to fully explain performance here the details of each pulley are as follows:

The upper half which includes a hub 3| and a half pulley flange 32 is pressed on to the upper end of sleeve 33. The lower pulley half 34 which also includes a hub 35 and a complementary half flange 36 is pressed on to the lower end of sleeve 33. Ball bearings 31 are pressed into each end of sleeve 33 and bear on shaft I5. Between the faces 32 and 36 of said pulley halves there is an axially slideable pulley part 46. This has a hearing thimble 4| which slides on the outside of sleeve 33 between the pulley faces 32 and 36. On the upper side it has a belt face 43 which is complementary to the upper pulley face 32, and on the lower side it has a belt face 44 which is complementary to lower pulley face 36. It is to be understood that pulley H has the same detailed structure. V belt which runs from a V belt groove on driving pulley 6 to the space between upper pulley half 30 and the intermediate shiftable pulley part 40 may be termed the motor driving belt. In the lower portion of pulley l2 betwen the lower face of shiftable pulley part 40 and the upper face 36 of lower pulley part 34 there is an intermediate belt 52 which runs between pulleys I2 and II. The opposite, or outer, end of this intermediate belt runs in the upper V belt groove of pulley I I; that is, between the faces of its upper pulley part and its shiftable pulley part. The lower grooved portion of pulley II receives the rear loop end of drill spindle pulley belt 53, an outer loop of which runs over a V belt groove in drill spindle pulley 8.

As above explained, the motion of shifting bracket l6 between the shafts I and 9 is forward and aft in a vertical plane between the shafts. To attain this motion, and to locate it in a position convenient to the user of the drill, I provide a link the inner end of which has a lug 6| fitted over shaft I4. The outer end of this link is pivotally attached to arm 63 at the inner end of manually operated shifting lever 64. Lever 64 is, in turn, pivoted on shaft 65 on supporting frame 66. The front portion of this frame has an arcuate surface 61 to afford space for indicia 68, to indicate speeds attained by the shifting motion of the assembly III. A pointer 69 on the outer end of lever 64 indicates positions of this lever on arcuate surface 61. Supporting frame 66 is affixed to the front end portion of head castmg 3 and held in place by screw 13. The outer end of lever 64 may be swung arcuately by handle 10. Twisting this handle will set shoe 12 at its inner end against arcuate surface 61 and hold lever 69 in the position desired.

In use, the device is mounted on a drill press column 2 as shown in Figures 1 and 2 and belts 50, 52 and 53 fitted over respective pulleys as above described. When the bracket I6 moves to ts extreme rearward limit of motion belt 56 runs in the outer portion of the upper groove space between faces 32 and 43 of pulley I2. Thus, if the upper groove of driving pulley 6 is of a smaller diameter than the effective diameter of the upper groove of pulley l2, there is a speed reduction between shaft I and pulley I2. Belt 52 in this position is crowded into the bottom of the lower groove portion of pulley I 2, between faces 44 and 36 of the pulley carts. and this lower groove is of small diameter compared with that of the outer effective grove of pulley II. The lower groove of pulley II receives belt 53 which runs near the hub of this pulley portion and over a somewhat larger V belt pulley groove on driven pulley 8. The speed reduction between shafts I and 9 is maximum in this position. There are three reducing ratios; first, betwen pulleys 6 and I2; second, between pulleys I2 and II; third. be tween pulleys I I and 8. Now, if lever 64 is swung counterclockwise (Figure 2) from the position in which it appears, then lever part 63 pulls link 60 and part ID from pulley 6 and shaft I and toward pulley 8 and shaft 9. When this is done the forward or outer loop of belt 59, which runs in the upper effective groove of pulley I2, moves shiftable pulley portion 40 downward as it crowds deeper into said upper effective groove. This downward motion of shiftable pulley portion 49 crowds the rear loop of intermediate belt 52 outward toward the rim of the lower effective groove of said pulley. This action in turn crowds the forward loop portion of belt 52 which runs in the upper effective groove of pulley II toward the hub of this pulley and this, in turn, similarly crowds the rear loop of belt 53 toward the rim of the lower effective groove of pulley II. The belts stay in the same tension because the pulley flanges of the grooves and effective grooves are all made at the same angle. The result of this action is that as the pulley assembly I0 moves forward bracket I6 occupies the space indicated by dotted line I6a in Figure 3. Pulleys II and I2 occupy the positions indicated by dotted lines Ila and I2a. Belt 50 will then be at the bottom of the upper effective groove of pulley I2 and will turn the pulley faster. Belt 52 will be at the outer portion of the effective lower groove of pulley I2 while the converse is true of this belt in the upper effective groove of pulley I I. Therefore, pulley II will turn faster. For the same reason the rear loop of belt 53, being crowded toward the periphery of lower effective groove of pulley II, will drive pulley 8 at a greater speed. There are therefore three increased ratios between the speeds of the several parts.

By this means the overall speed change ratio between shafts I and 9 can be as high as one to twelve; that is, if the position shown in Figure 2 be considered unity then when the mechanism assembly is moved to the position shown by dotted lines in Figure 3 the speed imparted to shaft 9 is twelve times that which it had in the first position.

It is to be observed that base bracket [6 in moving from the position shown in solid lines, Figure 3, to the position indicated by Mia is displaced upward somewhat due to the arcuate path in which the upper transverse pins of links I 8 travel. It is also apparent that upper pulley part 30 of pulley I 2 moves upward relative to belt 50. Belt 56 maintains the same horizontal position, however, and to keep it in this position the movable pulley part 40 slides downward on sleeve 33. It is this downward movement of part 40 that crowds the rear loop of belt 52 outward from the hub portion of the lower effective groove of this same pulley. At the same time the center pulley part of pulley II moves upward to accommodate the upward movement of the lower flanged pulley half of speed change pulley II, thus keeping belt 53 in its same horizontal plane as it moves to the outer part of the lower effective groove of this pulley. As illustrated, the speed change assembly I0 moves from a lower defenses usitionr sishowri'ahyasoiidiline iinitheliieures Qtl'1emQ iti0nsh0Wfi bvzddttedlli esi Fi ure-. ;Ehe- .bielt: system is,- .a1?rangd solltliat he be ts stay in the same horizontal position thro ighrout the movement indicated. gshould'lth move beyond "the vertical. :positicn 'shown by dotted lines, ,the effect 4 desired would: n'otlbe gained. I-Ioweverjt-here is-noneedfor his: as a suflicient longitudinal movementkbetweengthe drivingand driven pulleys" canv be ,gained by the movement .as shown. Obvio1J1sly, if--v lit becomes desirable to move theassemblydroms-theraised positiondfia to a lowered position forwardifrom. it (not shown) the position :onthe 'beltsi cang be ,changedrelativeto-the-grooveswhichtheyroccupy in the two speed changepulleys. ,ns'dllustrated, it is clearly apparent thattsince the horizontal position of belts fill-and 5.3a isanot changed during the speed varying motion theirtensionsmre not disturbed. This condition canbe attained by making thelength of linksgi-fl such that-the upward motion of the=transverse pins :28 ati h upper-ends equals: the drop which-takes place in the uppereffectivegroove of pulley 12V A-lso;the change which takes place in ,th-e ihorizontal -position of i thelower effective-groove of pulley I I is correspondingly varied. Thestructure here shown lends itself to, this desired arrangement.

' From the foregcingitwill be seen that' Ii have not only provided structure and mechanism. which -will produce a la rgevariationmin speed between the 'driv-ing and driven; shafts, .-but will also maintain the driving-and drivenbeltstfl and 53; :at the same tension -it hroug-hout the -speed .varying-motion. In view-of the foregoing l make the following claims.

- I' claim:

1. In a drill presshavinga vertical column supporting a head casting-wand a vertical drill spindle shaft carrying a V-bel-t pulleypn; the frontsame vertical plane; the-combination therewith of a speed ch'ange driving mechanism composed of a column bracket having a forwardly extendingztportionz attached to;v said columns ata-its'rear, a base bracketfor;speedechangepullcys disposed p sss m ma s eedc an e p lle haf a e brac e -.,disp,olse d the eabcve la yat ac e d to saidcolumn bracket by a pair ofgspacedlparallel linkss pivot ally eattached at ltheir' endsto said brackets eby ztliansverse ,pinspspeedlchange pulleyrshaftsumounted' in spaced relationship. on said.;base.-.bracket, with their axes extending in the same plane as. the' said drill spindle shaft and .driving pulley. shaft; speed .change pulleys ofthatype having axiallyf fixedl upper and lower hal andacomplementary pulley part axially shiftable between lsafid pulley halve lournalled on said speedchange pulley shafts;,al motoridriving V belt running over said driving V belt pulley and the .uppervgroovepfthe speed change pulley on said base'. bracket positioned adjacent .to\ .sai d-,-drivingipulley; an intermediate V belt runningsin th lowerggroove of said speed change pulleyianditheupper groove of. the. speed change pulleypositionedadjacent the driven V belt pulley on said drilllspindlepa .V belt running in the lower groove 50f -Sfiid-; speed. .change pulley and said-Vgbeltpulleyon said. d'r'ill spindle; a lever pivotally mounted on. airame on ,said drill head having-a manually ,operableshifting lever connectediby alinki tolsaid speed. change driving mechanismsshifting.it fore and an between said thepl'aneof the axes of said drill press 'sh'aftjand column; speed changepulleys-having'upper and I lower effective grooves and an axially shiftable centrally disposed pulley part mounted parallel in fore and aft spaced relation on said base bracket; a V belt extending from said motor shaft pulley to the upper groove of the aft pulley on said base bracket; an intermediate belt extending from the lower groove of said aft pul ley to the upper groove of said fore positioned pulley; a V belt pulley extending from the lower groove of said fore pulley to the pulley on said drill spindle; and manually operated lever and link mechanism for moving said speed change pulleys and base bracket fore and aft in the said plane of said drill spindle shaft and motor shaft and for holding said pulleys fixed at any position throughout said movement.

2. In a drill press having a vertical column, a.

head, a vertical drill spindle shaft carrying a driven V belt pulley operating on one side of said column and a driving V belt pulley mounted drill pressshaft and motor. shaft; an arcuate plate on: said. frame having an indicating scale end a -pointer. on said lever ,for indicating arcuate positionsi of said lever on said scale; said base bracket being disposed onsaidj links above said'polumn bracket so that as. it is shifted fore and-aft between-said driven. shaft and saidmotcpi' sl aftthe;speed= .changev pulleys. thereon are raised -and uloweredi by th'e rarcuate movement of p f -aidlinkszso that said belts ig between-thegv-rbelt pulley on said motor sh ft and the adjacentispeed change pulley, and the V:belt-gunning;between -the pulley on'the d l;spi r 1dleshaft and thmspeed change pulley ad acent thereto are wmaintained horizontal throughout theifore. and aft motionof said speed changegshiftmg motionimparted by said shiftnsever- 3; i111; a drill p ess l iaving a ,vertic'al column, a; head castin th reon ,extending fore v and: aft, a- -yerticaliidrill spindle -shafti having a' V belt Dll1lf9fltz IUDPWfQQQ P F Q t fore partuof said head casting; amotor shaft havin a V belt pulley on its upper end portion operating in the aft part of said head casting, speed change driving mechanism consisting of a column bracket attached to said drill press column having a forwardly extending portion to pivotally support a base bracket disposed above said column bracket and extending parallel thereto; a pair of links longitudinally spaced, extending between said column bracket and base bracket, and pivotally attached at their ends to said brackets to provide fore and aft motion for said base bracket between said spindle shaft pulley and said motor shaft pulley and vertical motion for said base bracket relative to said column bracket; a pair of V belt speed change pulleys having upper and lower V grooves formed on each side of an axiallyslidable pulley part, mounted fore and aft on said base bracket and operating on vertical shafts lying in a vertical plane which includes the axes of said drill spiny g dle shaft and motor shaft; a driving belt running from said motor shaft pulley to one of the grooves on said aft speed change pulley; an intermediate V belt running from the other groove on said aft speed change pulley to the groove on said fore speed change pulley in horizontal alignment with said driving belt; a driven V belt operating between the other groove on said fore pulley and spindle shaft pulley; and lever mechanism for moving said speed change driving mechanism fore and aft between said motor shaft and said spindle shaft to attain varying speeds between said shafts; said base bracket being disposed on said links so that the arcuate path of the upper ends thereof, during said fore and aft motion, imparts vertical motion to the speed change pulleys thereon maintaining said driving and driven belts horizontal throughout said shifting motion.

4. In a drill press having a. vertical column, a head casting thereon extending fore and aft, a vertical drill spindle shaft having a V belt pulley on its upper end operating within the fore part of said head casting, a motor shaft having a V belt pulley on its upper end portion operating in the aft part of said head casting, speed change driving mechanism consisting of a column bracket attached to said drill press col umn having a forwardly extending portion, a base bracket disposed above said column bracket and extending parallel thereto; a pair of links longitudinally spaced, extending between said column bracket and base bracket, and pivotally attached at their ends to said brackets to provide fore and aft and upward and downward motion for said base bracket between said spindle shaft pulley and said motor shaft pulley; a pair of V belt speed change pulleys having upper and lower V grooves formed on each side of an axially slidable pulley part, monted fore and aft on said base bracket and operating on vertical shafts lying in a vertical plane which includes the axes of said drill spindle shaft and motor shaft; a driving belt running from said motor shaft pulley to one of the grooves on said aft speed change pulley; an intermediate V belt running from the other groove on said aft speed change pulley to the groove on said fore speed change pulley in horizontal alignment with said driving belt; a driven V belt operating between the other groove on said fore pulley and spindle shaft pulley, and manually operated lever mechanism connected to said base bracket to move it fore and aft within predetermined limits so that the arcuate movement of said base bracket on said links provides vertical displace ment for said speed change pulleys to oifset the vertical change in the effective grooves of said pulleys when their speed ratio is changed so that said driving and driven belts will operate in the same plane throughout the shifting movement of said base bracket.

5. In a drill press having a vertical column supporting a head casting, and a vertical drill spindle shaft carrying a V belt pulley on the front side of said column, and a driving V belt pulley mounted on a vertical motor shaft on the back side of said column; the axes of said drill press shaft, motor shaft and said column being in the same vertical plane; the combination therewith of a speed change driving mechanism composed of a column bracket having a forwardly extending portion attached to said column at its rear, a base bracket for speed change pulleys disposed above said column bracket and supported by parallel, substantially vertical, links pivotally attached at their ends to said brackets to allow fore and aft movement of said base bracket in the plane of the axes of said drill press shaft and column and to provide vertical movement to maintain said speed change pulleys in a vertical position so that the belts extending from said motor pulley and drill press shaft are maintained in horizontal alignment throughout said speed change shifting movement; speed change pulleys having upper and lower efiective grooves and an axially shiftable centrally disposed pulley part mounted parallel in fore and aft spaced relation on said base bracket; a V belt extending from said motor shaft pulley to. the upper groove of the aft pulley on said base bracket; an intermediate belt extending from the lower groove of said aft pulley to the upper groove of said fore positioned pulley; a V belt pulley extending from the lower groove of said fore pulley to the pulley on said drill spindle; and manually operated lever and link mechanism for moving said speed change pulleys and base bracket fore and aft in the said plane of said drill spindle shaft and motor shaft and for holding said pulleys fixed at any position throughout said movement.

ROBERT D. PHARES.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,209,484 Tautz July 30, 1940 2,258,970 Buettell Oct. 14, 1941 2,267,238 Irwin Dec. 23, 1941 2,594,663 Lindell Apr. 29, 1952 

